Lifting-jack



(No Model.)

. T. L. CHAPMAN.

LIPTING JACK. N0. 336,793. Patented Feb. "23, 1886.

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o in the use of such devices.

UNITED STATES PATENT OFFICE.

THOMAS L. CHAPMAN, OF RICHMOND, VIRGINIA, ASSIGNOR OF ONE-HALF TOCLINTON LLOYD, OF WILLIAMSIORT, PENNSYLVANIA.

LlFTlNG-JACK.

SPECIFICATION forming part of Letters Patent No. 336,793, dated February23, 1886.

Application filed October 27, 1885.

Serial No. 181.083. (No model.)

To all whom, it may concern Be it known that I, THOMAS L. CHAPMAN,

a citizen of the United States, residing at Richmond, in the countyofHenrico and State 5 of Virginia, have invented certain new andusefulImprovements in Lifting-Jacks, of which the following is aspecification, reference being had therein to the accompanying drawings.

Figures 1 and 2 on the drawings represent vertical central sections ofthe present invention.

This device belongs to that class denominated lifting-jacks, and thenovelty consists in the peculiar construction of the device in itsseveral parts and in the device as a whole, all as will now be morefully set out and explained, reference being bad to the accompanyingdrawings.

In the drawings, A denotes the body of the jack,which is usually ofagenerallytriangular shape from top to bottom-that is, it is larger indiameter at the base than at the top. Centrally through the upper part,A, of the body is the screw-threaded aperture, Z), in which the screw Cis moved, and in the lower part of the body is the chamber F, of anydesired shape or size. This chamber is denominated the grease-chamber,because it is filled with any desired lubricant, and this is preferablydone through the aperture f in its base, which aperture is suitablyclosed by a plug, cover, or screw-cap, f, or the fillingaperture may beat the side. In some forms of construction it may be found desirable tofill this chamber through the screw-hole in the top, the chamber beingotherwise closed. Oircurnferentially about or around the base is aflange, a, on which the jack rests; but the jack may be so made as torest on a flat bottom, the under side of the bottom of the grease-chamber, being recessed or countersunk to take the screw cap or coveror plug of the filling-aperture. The head C of the 5 screw is providedwith the usual apertures, c, and 011 its upper end there is the usualswiveling head, D.

The detail of the operation of this device will be understood ata glanceby those skilled The grease-chamber having been properly filled and thescrew placed in its hole or socket, it is only necessary to screw it upand down onceor twice to thoroughly lubricate its entire thread and thesocket, and if at any time it is necessary to further lubricate thescrew-thread or socket the operation is repeated; but generally the mereuse of the screw will keep its socket and the whole stem suitablylubricated.

In ordinary construction it has been found very difiicult to keep thescrew of a liftingjack well 1ubricated,so as to be in good working orderfor any considerable time. This has chiefly happened because the body ofthe jack being open a considerable part of the screw has been exposed tothe air. Thus in cold weather the grease would harden, in hot weather itwould run off, and in dusty weather would get grimed. In addition tothese objections, any exposure of the jack will soon cause the screw torust; but in the present deviceall these difficulties are fullyobviated, and the screw is always in good working order. Nor does thepresent construction add in any perceptible manner to the weight or costof the device, while in all details of use it is adapted to everypurpose required of a liftingjack, and its real value as a tool orimplement very greatly increased.

Having now described my invention, what I consider new, and desire tosecure by Letters Patent, is

l. A liftingjack of otherwise ordinary construction, provided with agrease or lubricating chamber wherein the lower end of the screw works,substantially asdescribed.

2. A liftingjack having at its lower part a grease-cha1nber, F, with afilling-aperture provided with a suitable cover or plug to close it.

3. In a lifting-jack, the body A, having screw hole or socket b in itsupper part, and a grease-chamber, F, in its lower part, provided withsuitable filling-aperture adapted to be opened or closed, and the screw0, the whole constructed and combined in the manner and for the purposesdescribed.

In testimony whereof I afiix my signature in presence of two witnesses.

THOMAS L. CHAPMAN.

\Vitnesses:

W. J. HALLER, R. H. \VASHINGTON.

